1. Technical Field
The present disclosure relates to debug cards and method for diagnosing faults, and particularly to a debug card and method for diagnosing faults of a motherboard and a power supply unit.
2. Description of Related Art
Power on self test (POST) refers to routines that are immediately run after power is applied to an electronic device. During POST of a computer, a basic input output system (BIOS) of the computer sends POST codes to port 80 of an industrial standard architecture (ISA) bus. When a test item starts, a POST code is sent to the port 80; if the test item successfully completes, next POST code is sent to the port 80.
A debug card is a very useful tool for diagnosing faults of motherboard of the computer. The debug card is electronically connected to peripheral component interconnect (PCI) bus or ISA bus on the motherboard. Then the debug card receives POST codes via the bus, and the POST codes are successively displayed by a plurality of nixie tubes of the debug card. When the motherboard is faulted, the POST codes displayed by the plurality of nixie tubes cease to change. According to unchanged POST code displayed by the plurality of nixie tubes, technicians analyze specific fault reasons.
However, power supply unit (PSU) of the computer and the motherboard are relatively independent units. If faults of the PSU cause a fault of the motherboard, for example, the motherboard has no failure itself and the PSU malfunctioned, the unchanged POST code displayed by the plurality of nixie tubes will lead to a wrong diagnosis. Therefore, sometimes it is difficult for the technicians to use the debug card to analyze specific fault reasons accurately.
Therefore, there is a room for improvement within the art.